Monoazo dyes



Patented Dec. 9, 1Q47 2,433,403 MONOAZO DYES Friedrich Felix and Henri Riat, Basel, Switzerland, assignors to Society of Chemical Industry in Basic, Basel, Switzerland, a Swiss firm No Drawing. Applicationllanuary 23, 1945, Serial No. 574,209. In Switzerland February 2, 1944 It is known that valuable mordant dyestuffs are obtained by coupling 2:4-diaminobenzene-l-sulfonic acid with unsulfonated diazo compounds, such as e. g. those derived from l-hydroxy-2- amino-4:6-d'nitrobenzene or from 1-hydroxy-2- amfno-5-nitrobenzene. Such dyestuffs produce dyeings on the animal fiber which are changed by after-chroming into deep brown and then possess excellent wet fastnessproperties'besides good fastness to light.

According to this invention there are obtained dyestuffs which' are distinguished from these known products by essentially improved tinctorial properties when using as coupling components,

instead of the 2:4-diaminobenzene 1 sulfonic acid, compounds of the general formula l t-X wherein X stands for an alkyl, aralkyl or aryl group or for an amino group which may contain substituents. l

These coupling components which constitute new compounds are obtained for example by subjecting the 2:4 dinitrobenzeneel-sulfochloride SOT-X are, for example, 2:4-diaminobenzene-l-methylsulfone, 2:4 diamino benzene 1 ethylsulfone, 2:4 diaminobe nzen e 1 benzylsulfone, '2 4 diaminobenzene 1 g phenylsulfone, 2 :4-diaminobenzene l sulfamide, 2:4 diaminobenzene 1- diethylsulfamide, 2:4-diaminobenzene-1-phenylsulfamide and the like. If the new compounds 4 Claims. (01. 260-206) first of all to suitable reactions, such as'for example either reduction of the sulfochloride group contain a further aryl nucleus besidesthe aromatic radical containing the two amino groups standing in meta-position to each other, this may carry a group imparting solubility in water, such as for example a sulionic acid group. i

With regard to the diazotizing components, these may contain either sulfonic acid groups or be unsulfonated. The invention is not limited to the use of diazo compounds which are derived from ortho-amino-phenol or orthoaminonaphthalene. Quite generally there. can' be used such diazotizing components which contain an atom grouping in ortho-position to the diazotizable amino group which is capable of taking part in the formation of metal com-' plexes in the resulting azo-dyestufi. Examples of such diazotizing components are:--1-hydroxy- 2 aminobenzene, 1 hydroxy-2-amino-4-ch1orobenzene, 1 hydroxy 2 amino 4 nitro benzene, 1 hydroxy 2 amino 4:6 -dinitrobenzene, 1 hydroxy 2 amino 4:6 dichlorobenzene, 1 hydroxy 2 amino 324:5:6 tetrachlorobenzene, 1 hydroxy-.2-aminobenzene- 4-sulfonic acid, 1-hydroxy-2-amino-6-chlorobenzene 4 sulfonic acid, 1 hydroxy 2 amino-4- chlorobenzene 6 sulfonic acid, 1 hydroxy 2- amino 4 nitrobenzene 6 sulfonic acid, 1- hydroxy-2-amino-6-nitrobenzene-4-sulfonic acid, 1 -hydroxy- 2 -amino- 4 -methyl-benzene, l hydroxy 2 amino- 4 -methyl-benzene- 6 -sulfonic acid, 1 -hydroxy- 2 -amino- 4 -ch1oro-6-nitr0benzene, 1 hydroxy- 2 -amino-4-nitro-fi chlorobenzene and the like. Further in the napthalene series the d azo compound of 1-amino-2-hydroxynaphthalene-4-sulfonic acid and their nitrated and halogenated derivatives, and the 2-amino-1- hydroxynaphthalene-4 8-disulfonic acid.

Among ortho-aminocarboxylic acids are included:--- 1 aminobenzene 2 carboxylic acid, 2-aminonaphthalene-3-carboxylic acid, l-amino- 4-chlorobenzene-Z-carboxylic acid, 1-amino-4- nitrobenzene 2 carboxylic acid, 1 amino 4 acetylaminobenzene-Z-carboxylic acid, l-amino- 4:6r-dibromobenzene-2-carboxy1ic acid, and the like.

As mentioned above, the new dyestuffs are mordant dyes which dye the animal fibers yellow to red and brown shades which are changed by afterchroming into generally brown or deeper shadeswhich are characterized by excellent properties. Many of the new dyestufis possess the valuable and remarkable properties that they can be used in the one bath process with addition of chrome mordants.

The new dyestufis correspond therefore to the general formula SOs-Iv wherein R stands for an aromatic nucleus of the benzene or naphthalene series containing in or- ;tho-position to the --N=N-- group a carboxyl selected from the group consisting of alkyl radicals having at the most two carbon atoms,

CzHs

NE; and N but are not to be regarded as limiting itin any.

way,the parts being by weight.

Example 1 199 parts of 1-hydroxy-2-amino-4:"G-dinitrobenzene are diazotized in the usual manner at '50 C. and to this solution is 'added'a solution prepared from 136 parts'of 2:4-diaminobenzenel-methylsulfone, 100 parts of concentratedhydrochloric acid and 1500 parts of water. A concentrated solution of 550 parts of sodium'acetate is then added in order to bind the mineral acid. The mixture is stirred for 24 hours at 30C. and for 12 hours at 40 C. The dyestufi is precipitated in beautiful crystals. The whole is heated to 70 C., the dyestuff of the formula (I)H lTTHz is suction-filtered and Washed with warm Water until the filtrate is colorless. When dry, the dyestufi is obtained as a dark red powder. It dissolves sparingly in hot water, but very easily in a dilute solution of sod um carbonate to a red brown solution. Wool is dyed from an acid bath red orange tints which change by afterchroming into blackish brown. The same result is also obtained when working according to the one bath process.

Example 2 199 parts of 1-hydroxy-2-amino-4:G-dinitrobenzene are diazotized and the suspension of the diazo compound is coupled at 30 C. with a methyl alcohol solution of 200 parts of 2:4-diaminobenzene-l-ethylsulfone. The mineral acid is completely neutralized by a concentrated solu-' tion of sodium acetate. Coupling is complete after stirring for 18 hours at 30-40 C. The whole is heated to 70 C., the dyestufi of the formula SOzUrHs an acidibath red orange tints.

is suction-filtered and thoroughly washed with warm water. When dry, the dyestuff is a dark red "brown powder. It is easily dissolved in a .dilute solution of sodium carbonate to a red brown solution. The dyestufi dyes wool from By after-treating with chromium there is obtained a strong brown.

Instead of '-1-hydroxy-2-amino 4:6 dinitrobenzene there can also be used in the foregoing examples as diazotizing component 1-hydroxy-5- :nitro-Z-aminobenzene, 1 hydroxy 4 chloro-5- nitro-2eaminobenzene, 1 hydroxy 4 nitro 2- ;aminobenzene, l-hydroxy 4 chloro 2 aminobenzene, further 1-hydroxy-2-aminobenzene-4- sulfonic acid, 1 hydroxy 2 aminobenzene 4- sulfamide, 1 hydroxy z amino-l-chlorobenzene- 6-sulfonic acid, 1 -hydroxy 2 amino 4 nitro- I benzene-:fi-sulfonic acid, l-hydroxy-Z-amino-S- the following manner:

nitrobenzene-l-sulfonic acid, l-aminc-benzene-Z- carboxylic acid, 1 aminobenzene 2 carb-o-xylic acid-4- or -5-sulfonic acid, chlorinated or'brominated anthranilic acids andthe like.

The 2 4-diaminobenzene-l-alkylsulfones used as "coupling components have been prepared in 2:4:2':4'-tetranitro-diphenyl-disulfide produced from 2 :4-dinitrochlorobenzene and sodium disulfide is reduced in an alcohol solution with sodium sulfide and converted into the vthioether with an alkylating agent, such as for example dimethylsulfate or diethylsulfate. This is oxid zed in a solution of glacial acetic acid with hydrogen peroxide and the resulting sulfone is reduced with iron in usual manner.

The following process can also be adopted: 214:2:4'-tetranitro-diphenyl disulfide is reduced with sodium sulfide and the resulting 2 l-dinitrothiophenol is reacted with choroacetic acid to form 2:4-dinitro-thioglycolic acid. This is oxidized with .hydrogen peroxideto the corresponding sulfone, the carboxyl group is split off in known manner and the nitro groups are reduced to amino groups in known manner.

The 2:4-diaminobenzene-l-methylsulfone crystallizes from hot water in white laminae melting at C. The 2:4-diaminobenzene-l-ethylsulfone is recrystallized from dilute alcohol; it melts at 71- C.

Example 3 187 parts of 2:4-diaminobenzeneesulfamide are dissolved in 1500 parts of aqueous methyl alcohol of 50 per cent. strength and coupled at 30-40" C. with the diazonium salt from 199 parts of 1- hydroxy-2-amino-4zfi-dinitrobenzene. The solution is made neutral to cortgo by addition of solid sodium acetate. When coupling is complete, the Whole is heated to 70 C., the dyestufi of the formula OH NHz l S OzNHz is suction filtered and washed with warm'water. When-dry, it'islabrown powder which dissolved in a dilute solution of sodium carbonate to a red brown solution. It dyes Wool from an acid bath red brown'tints. When after-treated with'chrom'ium there is obtained a strong brown tint.

Example '4 "The diazonium salt from 199 parts of i-hy- 'droxy-2-amino-4:i6-dinitrobenzene is added at 30 C. to a warm methyl alcohol solution of 243 parts of 2:4-diaminobenzene-diethylsulfamide. After neutralizing with mineral acid, the solution is stirred with sodium acetate until the diazonium salt has disappeared. It is then heated to 70 C. and the dyestufi of the formula is suction-filtered and washed with warm water. The dry dyestuff forms a brown powder. It dissolves readily in a dilute solution of sodium carbonate. Wool is dyed from an acid bath redorange tints which change by after-chroming into a yellowish brown.

Instead of l-hydroxy-Z-amino-:B-dinitrobenzene there can be used in Examples 3 and 4 the diazotizing components named in the introduction or at the end of Example 2.

The sulfamides which have been used were prepared as follows:

2 :422' :4 tetranitro diphenyl disulfide obtained from 2:4-dinitrochlorobenzene and sodium disulfide is converted into 2: a-dinitrobenzene sulfochloride-by chlorination in an acetic acid suspension. The chloride is reacted with ammonia or an alkylamine, such as diethylamine, and the resulting dinitrosulfamides are reduced with iron in known manner.

The 2:4-diaminobenzenesulfamide crystallizes from water and has a melting point of 155 C.

The 2: 4-diaminobenzenediethylsulfamide crystallizes from dilute alcohol and melts at 80 C.

The following table indicates the shades of dyeings obtained with a further number of azo-dyestuffs produced according to the present invention:

6 The dyestufl. (15) of the above table in free form has the formula SOaH No,- OH 17111,

N=N NH:

/C2H5 OzN 1 i CzHa Erample5 100 parts of thoroughly wetted wool are introduced at C. into a dye-bath containing per 4000 parts of water, 2 parts of the dyestuff obtained according to Example 3, 2.5 parts of ammonium sulfate, 2.5 parts of sodium chromate and 10 parts of Glaubers salt, the temperature is raised to the boil within 30 minutes and dyeing is continued for hour at the boil. 0.5 to 1 per cent. of acetic acid of 40 per cent. strength is added and dyeing continued for a further hour. The wool is then rinsed and dried. It is dyed fast brown shades.

Example 6 100 parts of thoroughly wetted wool are introduced; at 60? G. into a dye-bath containing per 4000 parts of water, 2 parts of the dyestufi obtained according to Example 1, first paragraph, 4 parts of acetic acid of 40 per cent. strength and 10 parts of Glaubers salt, the temperature is raised to the boil within 30 minutes and dyeing is continued for 45 minutes at the boil. 1 part of sulfuric acid of 66 B. is added and the material is further dyed for 15 minutes at the boil. The dye-bath is cooled to about 70 0., 1. part of potassium bichromate is added, the bath is again heated to boiling and chroming is efiected for about 40 minutes at the boil. The wool is dyed fast brown shades.

Diazotizing Component Coupling Component Shades from an acid bath after-chromed (l2) 1-hydroxy-S-nitro-l-aminobenzene (13, l-hydroxy-4-nitro-2aminobcnzene (14) l-hydroxy-4-chloro-Q-aminobenzene 2:4-d1iaminobenzene-l-methylsulione o .do do 2:4-diaminobenzene-l-ethylsullone-- o o 2:4-diaminobenzcnesulfamide yellow orange strong violet brown.

yellow brown. reddish violet. yellow brown.

red brown violet brown. dull reddish yellow. yellow brown.

110 reddish violet brown.

. strong violet brown.

violet. brown. yellow brown. violet brown.

orange ..I

(15) l-hydroxy-4-nitro-2-aminobenzcne-6-sulfonic own acid.

The dyestuff (2) of the above table has the for- What we claim is: mula 1. An azo-dyestufi of the formula OH NH:

NE: N0, N=N NH:

RN=N NH,

SOz-CH:

The dyestuff (5) of the above table has the formula 70 which is free from sulfo groups and wherein R SOzCzHt Q nitro group, and :2: stands for an alkyl radical containing at the most 2 carbon atoms.

2,432,403, t 7 8 An azc dyestufiofthezformulm H REFERENCES CITED The following references are of record in the N02 N=NC -NH file of' this'patentf UNITED STATES PATENTS.

Son-12 Number Name Date 2,200,543 Dickey et a1 May 14, 1940 wherein :0 stands for an alkyl radical contaimng 1,893,557 Krzikaller Ian. 10, 1933 at the most 2 carbon atoms.

3. The dyestufi of the formula, FOREIGN PAIENTS Number Country Date 7 262,243 Great Britain Dec. 9, 1926 7 OTHER REFERENCES 8520B Soc. pour IIndustrie Chimique; 483,019, page Y 4, Feb. 27,1911. N02,-

42. 'l-hadyestufiiofithe formula;

0 11 N -Hi 1 A 8mm ERIEDRICHJFELIX. 9 HENRLRIAT; 

